Seismic Analysis of Multi-Storey RCC Building with and without Viscous Dampers

DOI : 10.17577/IJERTCONV10IS10028

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Seismic Analysis of Multi-Storey RCC Building with and without Viscous Dampers

1Jayadeep K S, 2Pramod Kumar Mahato, 3Dharmendra Kumar Sah, 4Baiju Prasad Gupta, 5Paon Thangjam

1 Assistant Professor, Department of Civil Engineering, R R Institute of Technology, Bangalore, India.

2,3,4,5UG Students, Department of Civil Engineering, R R Institute of Technology, Bangalore, India.

Abstract – Earthquake is the most important aspect to be considered in designing any building. During earthquake most structures are subjected to vibration. The vibrations may arise from wind forces, earthquake excitation, machine vibrations, or many other sources. In some cases, especially under strong earthquake excitations, these vibrations can cause structural damage or even structural collapse. By using dampers severe damages can be prevented. The concept of the viscous damper is to absorb the shocks and vibrations from the structure. However, the most important is the location of dampers which is the major consideration. Viscous damper is considered as the passive control systems used to dissipate and absorb energy induced during the earthquakes due to earthquake. The main purpose of application of dampers is to enhance the stiffness and stability of the structure and make the structure earthquake resistant. The present study is focused on the study of seismic behavior of building with the dampers and to evaluate seismic responses such as displacement, Storey drift and modal parameters. Three buildings (G+5), (G+10), (G+15) are analyzed by Dynamic Non-linear (Time-History method) using Cheerapunji earthquake acceleration data.

Keywords – Viscous dampers, Storey response

IINTRODUCTION

An earthquake is a powerful shaking of the earth's surface that can be fatal to thousands of people and cause serious damage. They are brought on by the unexpected release of energy from tectonic plate movements in the Earth's crust. Seismic waves are the means by which this power is discharged. The most severe and unanticipated natural calamities are earthquakes. In the worst situation, the large amount of energy produced during an earthquake may result in serious injury or the destruction of important structures. Civil constructions like high-rise buildings, skyscrapers, and long span bridges are designed with more flexibility as a result of the rapid economic development and modern technology, which increases their susceptibility to external excitation. Therefore, these flexible structures are susceptible to being exposed to extremely high levels of vibration in the event of a strong wind or earthquake. In order to keep such civil projects from suffering significant damage, the response reduction of civil structures during dynamic loads such large earthquakes and high winds has become a vital topic in structural engineering. The forces induced during the earthquakes should be resisted by the structures without suffering any major structural damage. All structures have to be designed to resist lateral loads in several ways. The most common lateral loads resisting systems are moment frames, shear wall and braced frame. Passive energy dissipating systems are also used as an alternative to seismic isolation which protects the

structures against the earthquakes. The application of such systems enhances the energy absorbing capacity of structures. The most common types of these systems include fluid viscous dampers, friction dampers, tuned mass dampers and metallic dampers.in the present study one of the passive energy dissipating devices is used and the seismic behaviour of the building is studied.

  1. VISCOUS DAMPERS

    Viscous dampers, also referred to as seismic dampers, are hydraulic components that diffuse kinetic energy induced during earthquakes and soften structural collisions. They are adaptable devices that can be made to provide for both controlled and uncontrolled dampening of structures to shield them from earthquake.

    Fig: 01 Viscous dampers

  2. Scope & Objectives: Scope of the study:

a) To perform the seismic analysis of multi storey RCC building with and without viscous dampers.

Objectives of the study:

  1. To study the Seismic behavior of building with and without dampers.

  2. To evaluate seismic responses such as Displacement, Storey drift and modal Parameters.

  3. To study the performance of building incorporated with dampers.

  4. To limit the parameters evaluated under permissible limits as per IS Provisions.

II. METHODOLOGY

  1. To carry out the proposed work 3 building models are considered (G+5, G+10 & G+15).

  2. The analysis is carried out considering the column supports fixed.

  3. The analysis is carried out by Dynamic Non-linear (Time

    -History Analysis) using Cheerapunji earthquake acceleration.

  4. The dampers are applied as Rigid links with required stiffness.

Fig: 02 Methodology flowchart

Table 01: Geometric details of the building

Number of storey

(G+5)

(G+10)

(G+15)

Storey height

3m

3m

3m

Height of the building

15m

30m

45m

Size of column

400*

400mm

500* 500mm

500*

500mm

No. of bays in X direction

6

6

6

No. of bays in Y direction

4

4

4

Spacing of bays in X direction

4m

4m

4m

Spacing of bays in Y direction

3m

3m

3m

Size of beam

200*

500mm

200*

500mm

200*

500mm

Thickness of slab

150mm

200mm

200mm

Grade of concrete

M25

M25

M25

Grade of steel

Fe 500

Fe 500

Fe 500

Live load (kN/m^2)

2

2

2

Floor finish (kN/m^2

1

1

1

Roof load (kN/m^2)

1.5

1.5

1.5

Damping ratio

5%

5%

5%

Fig: 03 Plan of building

Fig: 04 3D view of G+5 building

Fig: 05 3D view of G+10 building

Fig: 06 3D view of G+15 building

Fig: 07 Cheerapunji earthquake acceleration

  1. Date: Aug 06 1988

  2. Peak acceleration = -0.51100m/sec2 at 4.960sec

  3. Duration of earthquake 22seconds

  4. 1064 Acceleration data points at 0.020secs interval.

    Table 02: Damper properties

    Models

    K (kN/m)

    Mass(kN)

    G+5

    62426.070

    48

    G+10

    72841.580

    62

    G+15

    82692.895

    79

    Fig: 08 G+5 Building with dampers applied at alternate storey

    Table 03: Displacement of G+5 Building

    Storey

    Elevation (m)

    Displacement (mm) without dampers

    Displacement (mm) With dampers

    X-Dir

    Y-Dir

    X-Dir

    Y-Dir

    5

    15

    44.17

    39.97

    25.62

    23.58

    4

    12

    39.71

    35.34

    23.03

    20.85

    3

    9

    31.95

    27.47

    18.53

    16.21

    2

    6

    22.04

    19.99

    12.78

    11.79

    1

    3

    10.03

    9.24

    5.82

    5.45

    0

    0

    0

    0

    0

    0

    Fig: 09 Displacement v/s storey Height for G+5 building

    1. The graph shows displacement v/s height of the building for G + 5 building with dampers applied at alternate storeys.

    2. The permissible displacement as per IS code is (H/500) i.e, (15000/500) = 30mm

    3. The maximum displacement obtained is 25.62mm in X-direction.

    4. The displacement obtained was 44.17mm without dampers and with the application of dampers the displacement has been reduced to 25.62mm.

    5. Application of viscous dampers have reduced the displacement by 42%

CASE

Modes

Time period (secs)

Frequency (cycles/sec)

WOD

WD

WOD

WD

Modal

1

0.76

0.53

1.315

1.886

Modal

2

0.719

0.512

1.391

1.953

Modal

3

0.67

0.47

1.492

2.127

Table 04: Modal Parameters of G+5 building

Fig: 10 G10 Building with dampers applied at alternate storey

Table 05: Displacement of G + 10 Building

Storey

Elevation (m)

Displacement (mm)

without dampers

Displacement (mm)

With dampers

X-Dir

Y-Dir

X-Dir

Y-Dir

10

30

94.15

78.34

52.72

43.87

9

27

92.53

76.45

51.81

42.81

8

24

89.51

73.63

50.13

41.23

7

21

85.01

69.62

47.61

38.99

6

18

78.66

64.23

44.05

35.97

5

15

70.76

57.72

39.62

32.32

4

12

61.73

50.16

34.57

28.09

3

9

51.68

41.72

28.94

23.36

2

6

40.30

32.64

22.57

18.28

1

3

26.34

21.60

14.57

12.09

0

0

0

0

0

0

CASE

Modes

Time period (secs)

Frequency (cycles/sec)

WOD

WD

WOD

WD

Modal

1

1.524

1.236

0.656

0.809

Modal

2

1.42

1.224

0.704

0.816

Modal

3

1.325

1.102

0.755

0.907

Table 06: Modal Parameters of G + 10 building

Fig: 11 Displacement v/s storey Height for G+10

building

  1. The graph above shows displacement v/s height of the building for G + 10 building with dampers applied at alternate storeys.

  2. The permissible displacement as per IS code is (H/500) i.e, (30000/500) = 60mm

  3. The maximum displacement obtained is 52.72mm in X-direction.

  4. The displacement obtained was 94.14mm without dampers and with the application of dampers the displacement has been reduced to 52.72mm.

  5. Application of viscous dampers have reduced the displacement by 44.65%

Fig: 12 G+15 Building with dampers applied at alternate storey

Table 07: Displacement of G + 15 Building

Stor ey

Elevation (m)

Displacement (mm)

without dampers

Displacement (mm)

With dampers

X-Dir

Y-Dir

X-Dir

Y-Dir

15

45

138.13

124.65

74.59

67.31

14

41

135.1

120.69

72.96

65.17

13

39

130.5

115.53

70.47

62.39

12

36

124.72

109.49

67.35

59.13

11

33

118.37

104.09

63.92

56.21

10

30

112.13

99.54

60.55

53.75

9

27

106.4

94.05

57.45

50.79

8

24

100.11

87.52

54.06

47.26

7

21

93.65

80.23

50.57

43.33

6

18

86.49

72.78

46.7

39.3

5

15

78.33

64.86

42.3

35.03

4

12

69

56.63

37.26

30.58

3

9

58.15

47.37

31.4

25.58

2

6

45.67

37.09

24.66

20.03

1

3

30.04

24.76

16.22

13.37

0

0

0

0

0

0

Fig: 13 Displacement v/s storey Height for G+15 building

CASE

Modes

Time period (secs)

Frequency (cycles/sec)

WOD

WD

WOD

WD

Modal

1

2.083

1.925

0.48

0.519

Modal

2

2.019

1.836

0.495

0.544

Modal

3

1.868

1.662

0.535

0.601

Table 08: Modal Parameters of G + 15 building

a) The graph above shows displacement v/s height of the building for G + 15 building with dampers applied at alternate storeys.

  1. The permissible displacement as per IS code is (H/500) i.e., (45000/500) = 90mm

  2. The maximum displacement obtained is 74.59mm in X-direction.

  3. The displacement obtained was 138.12mm without dampers and with the application of dampers the displacement has been reduced to 74.59mm.

  4. Application of viscous dampers have reduced the displacement by 46%

CONCLUSION:

  1. The study shows that the structure evaluated with the application of dampers to be efficient and Viscous dampers can serve as better energy dissipating device.

  2. It can be concluded that, with the application of viscous dampers the seismic performance of the structures can be improved against earthquakes.

  3. The seismic responses such as Displacement, drift increases as the seismic zones changes for II to V.

  4. Non-Linear dynamic analysis shows the actual response of the structure subjected to earthquakes.

  5. The building models considered for the study shows higher responses during Non-Linear dynamic analysis and by application of dampers the responses have been reduced under permissible limit.

  6. In G+5 building with the application of Viscous dampers we can see a reduction of displacement by 42%.

  7. In G+10 building with the application of Viscous dampers we can see a reduction of displacement by 44.65%.

  8. In G+15 building with the application of Viscous dampers we can see a reduction of displacement by 46%.

  9. Storey drift of all the buildings is within the permissible limit of 0.004H.

  10. Application of Viscous dampers significantly increases the stability and stiffness of the structures.

REFERENCES:

[1] seismic design of multistorey RCC building with dampers using etabs.b .naresh , j .omprakash p.g. student, department of civil engineering, dr. k. v .subba reddy institute of technology, duapdu, andhra pradesh, india (vol. 7, issue 1, January 2018).

[2] seismic performance of steel moment-resisting frame retrofitted with linear and nonlinear viscous dampers bryan chalarca, andré filiatrault, daniele perrone(2019), university school for advanced studies iuss pavia, pavia, Italy.

[3] performance of fluid viscous dampers on seismic response of rcc structures md mujeeb, j s r prasad, venu malagavelli (international journal of innovative technology and exploring engineering (ijitee) issn: 2278-3075, volume-8 issue-12, october, 2019)

[4] seismic analysis of multi storey rc building with and without fluid viscous damper varun m, b s suresh chandra (international journal of trend in scientific research and development (ijtsrd) volume 4 issue 6, september-october 2020.

[5] study on the effect of viscous damper for rcc frame structure puneeth sajjan, praveen biradar student, department of civil engineering, blde cet, vijaypur, karnataka, india volume: 05 issue: 09

| sep-2016.

[6] seismic response of rc structures using different types of dampers,

k. jaya gayathrri dhevi & dr. k rama mohana rao post graduate student, department of civil engineering, jawaharlal nehru technological university, kukatpally, hyderabad 2018

[7] analysis of building using viscous dampers in seismic zone- vabhishek kumar maurya, v.k. singh, international journal of advances in mechanical and civil engineering, issn: 2394-2827 volume-5, issue-3, jun.-2018.

[8] seismic analysis of building using dampers in shear walls . kapil p. gunjal , prof. sanket s. sangha, international journal of innovations in engineering and science, vol. 4, no.6, 2019.